The invention relates to a method for fire-fighting, the method comprising: piercing a shell of a burning object by pushing at least one elongated piercing tool arranged in a rescue boom from the side of a first surface of the shell to the side of a second surface thereof; feeding, along at least one longitudinal channel in the piercing tool, a fire extinguishing medium to a nozzle provided in the piercing tool; and spraying the fire extinguishing medium to the side of the second surface of the shell through a plurality of orifices provided in the nozzle.
The invention further relates to a rescue boom comprising: a boom provided with at least one movable boom part connected to a base; at least one piercing tool arranged at a free end of the boom, the piercing tool being an elongated piece comprising at least one longitudinal channel; at least one actuator for moving the piercing tool in the longitudinal direction of the piercing tool with respect to an outermost end of the boom; at least one feed channel for feeding a fire extinguishing medium to the channel in the piercing tool; and at least one nozzle, which is an elongated piece and which is connected to the channel in the piercing tool, the fire extinguishing medium being arranged to be fed through a plurality of orifices provided in the nozzle.
The invention still further relates to a nozzle of a piercing tool for spraying a fire extinguishing medium, the nozzle being an elongated piece having a front end and a rear end and the nozzle comprising: fastening means at the rear end of the nozzle for fastening the nozzle to the piercing tool; at least one feed channel for feeding a fire extinguishing medium to the nozzle; and a plurality of orifices extending from the feed channel to an outer surface of the nozzle, the orifices being directed obliquely forwards such that the farther away from the front end of the nozzle a single orifice resides, the larger an acute angle between the middle axis of the orifice and the middle axis of the nozzle.
In fire-fighting, it is extremely important to get the extinguishing measures started quickly, before a fire gets out of control. In aircraft accidents, for example, a fire should be brought under control no later than during the first couple of minutes from the outset of the fire. In such a case, the fire-fighting equipment must be brought to the scene of fire without delay, and a fire extinguishing medium is to be fed quickly and without deconstruction of structures to the interior of a burning object. Thus, rescue booms arranged on a movable base have been provided that are equipped with a piercing tool capable of penetrating through the wall construction of a burning object. A piercing tool provided with a sharp tip is relatively easily capable of piercing the shell structures of vehicles or the like. After piercing, a fire extinguishing medium can be fed through the piercing tool directly to the burning object. In the prior art equipment, a fire extinguishing medium is sprayed through nozzles provided in the piercing tool evenly in every direction such that the shape of the resulting jet is circular. In practice, it has been found that such a shape of a jet is insufficient in situations where a fire is to be effectively prevented from expanding. The problem is thus the directing of a fire extinguishing medium jet.